github.com/google/syzkaller@v0.0.0-20251211124644-a066d2bc4b02/sys/linux/test/amd64-syz_kvm_nested_vmresume (about)

     1  #
     2  # requires: arch=amd64 -threaded
     3  #
     4  r0 = openat$kvm(0, &AUTO='/dev/kvm\x00', 0x0, 0x0)
     5  r1 = ioctl$KVM_CREATE_VM(r0, AUTO, 0x0)
     6  r2 = syz_kvm_setup_syzos_vm$x86(r1, &(0x7f0000c00000/0x400000)=nil)
     7  
     8  # Create a nested VM that performs INVD (0f 08) and HLT (f4) to test vmresume.
     9  # INVD is one of the few instructions that cause unconditional VM exit on Intel.
    10  # On AMD, SYZOS also turns on INVD interception.
    11  #
    12  r3 = syz_kvm_add_vcpu$x86(r2, &AUTO={0x0, &AUTO=[@enable_nested={AUTO, AUTO, 0x0}, @nested_create_vm={AUTO, AUTO, 0x0}, @nested_load_code={AUTO, AUTO, {0x0, "0f08f4"}}, @nested_vmlaunch={AUTO, AUTO, 0x0}, @nested_vmresume={AUTO, AUTO, 0x0}], AUTO})
    13  r4 = ioctl$KVM_GET_VCPU_MMAP_SIZE(r0, AUTO)
    14  r5 = mmap$KVM_VCPU(&(0x7f0000009000/0x1000)=nil, r4, 0x3, 0x1, r3, 0x0)
    15  
    16  # L2 VM executes INVD. Exit reason is mapped to 0xe2e20002.
    17  #
    18  ioctl$KVM_RUN(r3, AUTO, 0x0)
    19  syz_kvm_assert_syzos_uexit$x86(r5, 0xe2e20002)
    20  
    21  # L1 resumes L2, which executes HLT. Exit reason is mapped to 0xe2e20001.
    22  #
    23  ioctl$KVM_RUN(r3, AUTO, 0x0)
    24  syz_kvm_assert_syzos_uexit$x86(r5, 0xe2e20001)
    25  
    26  # guest_main should finish with guest_uexit(-1).
    27  #
    28  ioctl$KVM_RUN(r3, AUTO, 0x0)
    29  syz_kvm_assert_syzos_uexit$x86(r5, 0xffffffff)